The present invention pertains to an exercise machine, more particularly, a ski exercise machine.
The major technical problem in the designs of ski exercise machines with ski poles derives from the considerable torque generated by the movement of the long lever arms of the ski poles, particularly when the point from which the poles extend vertically is spaced from the longitudinal axis of the machine.
Even a moderate arm resistance at the handgrip translates into significant torque at the bottom of the pole where the resistance has to be applied. This causes difficulty when it is desired that the arm poles simply fold down for storage, because pull pins, wing nuts or other sufficiently strong complicated connections usually must be disassembled before folding.
The existence of the large movement at the connecting points of the arm poles to the structure of the ski exercise device means the skier frame has to be able to withstand cylindrical torque as well as other torques in opposing directions.
A representative prior art cross-country ski exercise device is disclosed in U.S. Pat. No. 4,804,178, issued to Friedebach on Feb. 14, 1989. This patent is for a ski exercise device which is complex in assembly of the components. The center of gravity of the poles with respect to the foot skates is transferred down to the outer ends of the device.
The ski exercise machine of the present invention overcomes problems not addressed in prior art by providing a unique resistance belt system and a unique arm pole system. The poles originate close to the center line of the machine. The resistance belt system provides for greater leg resistance and is substantially concealed by the elevated center track without increasing manufacturing costs. The present invention provides smoother leg movement, more available arm resistance, and more available leg resistance. The arm poles are one piece, with provision for gripping by users of various heights, and provide a firm grip with no wiggling between separate parts as in the prior art arm poles. The exercise machine of the present invention is quieter and more durable than comparably priced prior art machines.